RESPONSES TO IRON-DEFICIENCY IN ARABIDOPSIS-THALIANA - THE TURBO IRONREDUCTASE DOES NOT DEPEND ON THE FORMATION OF ROOT HAIRS AND TRANSFERCELLS

Citation
Pr. Moog et al., RESPONSES TO IRON-DEFICIENCY IN ARABIDOPSIS-THALIANA - THE TURBO IRONREDUCTASE DOES NOT DEPEND ON THE FORMATION OF ROOT HAIRS AND TRANSFERCELLS, Planta, 195(4), 1995, pp. 505-513
Citations number
30
Categorie Soggetti
Plant Sciences
Journal title
PlantaACNP
ISSN journal
00320935
Volume
195
Issue
4
Year of publication
1995
Pages
505 - 513
Database
ISI
SICI code
0032-0935(1995)195:4<505:RTIIA->2.0.ZU;2-N
Abstract
Arabidopsis thaliana (L.) Heynh. Columbia wild type and a root hair-le ss mutant RM57 were grown on iron-containing and iron-deficient nutrie nt solutions. In both genotypes, ferric chelate reductase (FCR) of int act roots was induced upon iron deficiency and followed a Michaelis-Me nten kinetic with a K-m of 45 and 54 mu M Fe-III-EDTA and a V-max of 4 2 and 33 nmol Fe2+.(g FW)(-1).min(-1) for the wild type and the mutant , respectively. The pH optimum for the reaction was around pH 5.5. The approximately four fold stimulation of FCR activity was independent o f formation of root hairs and/or transfer cells induced by iron defici ency. Iron-deficiency-induced chlorosis and the development of a rigid root habit disappeared when ferric chelate was applied to the leaves, while FCR activity remained unchanged. The time course of the respons es to iron deficiency showed that morphological and physiological resp onses were controlled separately.